The first computer spreadsheet program was introduced in 1979, allowing users to perform complex computations using an expressive but very easy to learn formula language in comparison to computer programming languages: for that reason, they remain the preferred calculation tool for non-computer scientists. Collaboration-enabled spreadsheets, allowing multiple users to collaborate simultaneously on a single spreadsheet document, show a latent need for collaborative calculation over data that is currently limited by the required free sharing of data, opening the possibility of loss and theft of very valuable information: to solve these problems, a secure spreadsheet that preserves and enhances the privacy and ownership of data is disclosed.
Multiple variations and models of secure multi-party protocols have been published in the cryptographic literature: security assumptions (computational vs unconditional), adversarial models (active vs passive, static vs adaptative), underlying cryptographic primitives (garbled circuits, oblivious transfers, secret sharing, homomorphic encryption, oblivious random access machines), communication models (secure channels, broadcast), and delegatable execution (outsourcing to the cloud, trusted hardware). It would be of great utility to abstract away all these models of secure computation, so that the user is able to configure different security parameters and security scenarios without impacting the support for secure computation of the formulas taken from spreadsheet software packages; more specifically, users should be able to outsource the computation to one or multiple cloud systems instead of using their own computers, with the aim of speeding up secure computations.
It is therefore an object of the present disclosure to provide various models of security computation under the graphical interface of the spreadsheet paradigm, allowing an easy, fast and convenient to securely calculate for the non-cryptographer.